Blade holding device, assembly including the same, and method of operating associated thereto

ABSTRACT

A blade holding device for selectively and adjustably maintaining a contact pressure onto a neighboring roller, such as the ones used in machines of the pulp and paper industry, and other like industries. The blade holding device includes a base, a hinge, a support plate, a blade, and biasing means. The hinge has first and second components, the first component being mounted onto the base, and the second component being pivotally moveable with respect to the first component. The support plate is preferably mounted onto the second component of the hinge, and is thus pivotally moveable with respect to the base. The blade is preferably removably mountable onto a front portion of the support plate and is operable between a contact position where the blade rests against the roller for maintaining the contact pressure, and a retracted position where the blade is drawn away from said roller from removing the contact pressure. The biasing means are used for operatively connecting between the base and the support plate for biasing the support plate and corresponding blade into the contact position. The blade of the blade holding device may thus follow the roller continuously throughout a greater change in diameter and with little or no maintenance.

FIELD OF THE INVENTION

The present invention relates to a blade holding device. More particularly, the present invention relates to a blade holding device such as the ones employed to cooperate with rollers of machines used in the pulp and paper industry, and other like industries. The present invention also relates to an assembly, such as a machine for example, provided with the device and corresponding rollers, as well as to a method of operating associated thereto. The present patent application claims priority of patent application No. CA 2,440,903, filed Sep. 16^(th), 2003, the content of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

It is known in the art that a paper machine such as the ones used in the pulp and paper industry, generally comprises an important number of rollers that have different utilities. Typically, the rollers must be cleaned by means of scrapers. Each scraper is generally provided with a blade-holder which contains an interchangeable blade, and each blade-holder must generally carry out a constant pressure or some kind of contact pressure on the roller via the blade so as to be able to properly clean the surface of the roller.

These types of blade-holders have been used in the industry of pulp and paper for many years now. Known in the art are two main types of blade-holders, namely: a) flexible blade-holders whose loading system operates by means of a hose filled with air, glycol, silicon, or the like; and b) rigid blade-holders which are not provided with such a direct loading system. The main function of blade-holders is to retain a blade onto a corresponding roller and enable the blade to clean the roller while keeping a contact pressure when the roller turns. In order to carry out the cleaning, the blade must typically be in compression (loaded) on the roller, and it is for this reason that the compression or loading system of a blade-holder is very important.

Also known in the art are DST and KF blade-holders, and the various disadvantages associated thereto, namely the fact that they require a hose for operation thereof, the hose drying up after a certain service time, which requires substantial maintenance, and thus in turn prevents production of paper, as well as the fact that these blade-holders generally require the assistance of a control box for proper operation thereof, and thus complicated electronics and corresponding maintenance and servicing thereof are required, and the like, which is also very disadvantageous for obvious reasons.

Also known to the Applicant are the following US patents and/or patent applications describing different blade holding devices: U.S. Pat. Nos. 3,144,674; 3,377,644; 3,778,861; 3,800,357; 3,866,266; 4,151,797; 4,367,120; 4,444,102; 6,120,649; 6,328,853 B1; 6,389,669 B1; 6,547,932 B1; 6,749,725 B1; and 2004/0149414 A1.

Also known in the art are the disadvantages associated with some of the blade holding devices described in the above-mentioned documents, namely the fact that: a) an intricate design and complex cooperation between the components prevent them from being easily interchangeable and/or serviced, particularly when the blade needs to be replaced; b) because of their intricate design, any debris from the roller which may find itself accumulated onto the blade holding device and the components thereof may prevent proper operation of the blade holding device; c) the blade holding devices and corresponding blades thereof are not intended to follow the roller through a substantial change in diameter of the roller, thereby requiring the positioning of the blade holding device and/or the frequent replacement of different sized blades; d) the blade holding devices generally comprise projecting components which may adversely cooperate with the rollers, with debris accumulated thereon, and with other components of the assemblies in which they are used; e) the blade holding devices are not intended to have their blades maintain, in a continuous manner, a contact pressure on the rollers, and this throughout a wide range of roller diameters; and f) the blade holding devices are not devised to allow the blade to be easily, quickly, and adjustably operated between contact positions and retracted positions.

Hence, in light of the aforementioned, there is a need for a improved blade holding device which, by virtue of its design and components, would be able to overcome some of the aforementioned prior art problems.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a device which satisfies some of the above-mentioned needs and which is thus an improvement over other related blade holding devices known in the prior art.

In accordance with the present invention, the above object is achieved, as will be easily understood, with a blade holding device for selectively and adjustably maintaining a contact pressure onto a neighboring roller, the device comprising:

-   -   a base;     -   a hinge having first and second components, the first component         being mounted onto the base, and the second component being         pivotably moveable with respect to the first component about a         pivot axis;     -   a support plate, said support plate being mounted onto the         second component of the hinge, and thus being pivotably moveable         with respect to the base;     -   a blade being removably mountable onto a front portion of the         support plate, the blade being operable between a contact         position where the blade rests against the roller for         maintaining the contact pressure, and a retracted position where         the blade is drawn away from said roller for removing the         contact pressure; and biasing means, the biasing means being         operatively connected between the base and the support plate for         biasing the support plate and corresponding blade into the         contact position.

According to another aspect of the invention, there is also provided an assembly comprising:

-   -   a roller; and     -   a blade holding device positioned adjacent to the roller for         selectively and adjustably maintaining a contact pressure onto         said roller, the device comprising:         -   a base;         -   a hinge having first and second components, the first             component being mounted onto the base, and the second             component being pivotably moveable with respect to the first             component about a pivot axis;         -   a support plate, said support plate being mounted onto the             second component of the hinge, and thus being pivotably             moveable with respect to the base;         -   a blade being removably mountable onto a front portion of             the support plate, the blade being operable between a             contact position where the blade rests against the roller             for maintaining the contact pressure, and a retracted             position where the blade is drawn away from said roller for             removing the contact pressure; and     -   biasing means, the biasing means being operatively connected         between the base and the support plate for biasing the support         plate and corresponding blade into the contact position.

Preferably, the blade holding device comprises retracting means for operating the support plate and corresponding blade into the retracted position. The retracting means may take on various suitable embodiments according to the present invention, as will be explained in greater detail hereinbelow.

For example, and preferably, the retracting means comprise:

-   -   a hinge having first and second components, the first component         being mounted onto the base, and the second component being         pivotably moveable with respect to the first component about a         pivot axis; and     -   a lever, said lever being mounted onto the second component of         the hinge of the retracting means, and thus being pivotably         moveable with respect to the base, said lever having a front         portion cooperating with a rear portion of the support plate for         displacing the same so as to reactively displace the front         portion of the support plate and corresponding blade away from         the roller, into the retracted position.

Preferably also, the retracting means comprise a retracting arm, the retracting arm being pivotably mountable onto the base and being provided with a cam, the cam being positioned adjacent to the lever, and being shaped and sized so that when the retracting arm is operated into a first configuration, the cam is away from said lever, thereby enabling the biasing means to bias the support plate and corresponding blade into the contact position, and when the retracting arm is operated into a second configuration, the cam presses against the lever so as displace the same, and in turn displace the support plate and corresponding blade into the retracted position.

Preferably also, the biasing means comprise a plurality of springs disposed along a transversal width of the support plate, in a direction substantially parallel to the pivot axis of the hinge supporting the support plate.

Preferably also, the biasing means comprise a casing for containing the springs within said casing.

Preferably also, the casing comprises first and second parts, said parts being nestable into one another and being slidably movable with respect to each other so as allow the springs to either expand or be compressed within the casing.

According to yet another aspect of the invention, there is also provided a method of operating the above-mentioned blade holding device and/or assembly.

According to yet another aspect of the invention, there is also provided a kit with components for assembling the above-mentioned blade holding device and/or assembly.

The objects, advantages and other features of the present invention will become more apparent upon reading of the following non-restrictive description of preferred embodiments thereof, given for the purpose of exemplification only, with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a blade holding device according to a preferred embodiment of the present invention, the blade holding device being shown with its blade in a contact position with a neighbouring roller.

FIG. 2 is another side view of what is shown in FIG. 1, the blade of the blade holding device being now shown in a contact position after the roller has decreased in diameter.

FIG. 3 is another side view of what is shown in FIG. 1, the blade holding device being now shown with its blade in a retracted position.

FIG. 4 is an enlarged view of the blade holding device shown in FIG. 1.

FIG. 5 is another side view of what is shown in FIG. 1, the blade holding device being now shown provided with retracting means according to a preferred embodiment of the present invention.

FIG. 6 is another side view of what is shown in FIG. 5, the blade holding device being now shown with its blade in a retracted position via an operation of the retracting means.

FIG. 7 is a side view of a blade holding device according to yet another preferred embodiment of the present invention, the biasing means thereof being shown operatively connected between a front portion of the base and a front portion of the support plate.

FIG. 8 is a side view of a blade holding device according to yet another preferred embodiment of the present invention, the biasing means thereof being shown with a portion pivotally connected to the base and another portion operatively connected to a component of a rear portion of the support plate.

FIG. 9 is a side view of a blade holding device according to yet another preferred embodiment of the present invention, the biasing means thereof being shown with an end in abutment with a L-shaped plate securely connected to the base of the device, and another end operatively connected to the support plate via triangular-shaped cams.

FIG. 10 is a side view of a blade holding device according to yet another preferred embodiment of the present invention, the biasing means thereof being shown with one end connected to a rear portion of the support plate and another end connected to a flange positioned above the support plate and removably connectable onto the base of the blade holding device.

FIG. 11 is a side view of a blade holding device according to yet another preferred embodiment of the present invention, the biasing means thereof being shown operatively connected between the base and the support plate.

FIGS. 12 to 14 illustrate different embodiments of biasing means which could be used with the blade holding device shown in FIG. 11.

FIG. 15 is a side view of a blade holding device according to yet another preferred embodiment of the present invention, the biasing means thereof comprising a rotatable magazine positioned within a recess of the base, said magazine comprising a plurality of casings each comprising within a set of springs of different biasing force.

FIG. 16 is an exploded view of a casing with corresponding biasing means to be contained therein and fasteners according to a preferred embodiment of the present invention.

FIG. 17 is a front plan view of what is shown in FIG. 16, the casing, biasing means, and fasteners being now shown in an assembled configuration.

FIG. 18 is a side view of what is shown in FIG. 17.

FIG. 19 is a front plan view of a casing according to yet another preferred embodiment of the present invention, said casing including piston cylinders for allowing the first and second parts of the casing to be slidably moveable with respect to each other.

FIG. 20 is an elevational view of a piston cylinder shown within the casing of FIG. 19.

FIG. 21 is an exploded view of what is shown in FIG. 20.

FIG. 22 is a side view of a casing and corresponding biasing means contained within according to yet another preferred embodiment of the present invention.

FIG. 23 is an exploded view of what is shown in FIG. 22.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

In the following description, the same numerical references refer to similar elements. The embodiments and physical dispositions shown in the figures and/or described herein are preferred, and are used for exemplification purposes only.

Moreover, although the present invention was primarily designed for use with machines and rollers of the pulp and paper industry, it may be used with other type of objects and in other different fields, as apparent to a person skilled in the art. For this reason, expressions such as “roller”, “pulp”, “paper”, “blade”, etc. used herein should not be taken as to limit the scope of the present invention and includes all other kinds of items and/or applications with which the present invention could be used and may be useful.

Moreover, in the context of the present invention, the expressions “device”, “system”, “holder”, and any other equivalent expression and/or compound word thereof known in the art will be used interchangeably. Furthermore, the same applies for any other mutually equivalent expressions, such as “assembly”, “apparatus” and “machine”, as well as “spring” and “biasing means” for example, as also apparent to a person skilled in the art.

In addition, although the preferred embodiment of the present invention as illustrated in the accompanying drawings comprises various components and although the preferred embodiment of the blade holding device 1 as shown consists of certain geometrical configurations as explained and illustrated herein, not all of these components and geometries are essential to the invention and thus should not be taken in their restrictive sense, i.e. should not be taken as to limit the scope of the present invention. It is to be understood, as also apparent to a person skilled in the art, that other suitable components and cooperations thereinbetween, as well as other suitable geometrical configurations may be used for the blade holding device 1 and corresponding components according to the present invention, as briefly explained and inferred herein, without departing from the scope of the invention.

Broadly described, the present invention, as shown in the accompanying drawings, relates to a blade holding device 1 for selectively and adjustably maintaining a contact pressure onto a neighbouring roller 5, such as the ones used in machines of the pulp and paper industry, and other like industries. It is to be understood that, in the context of the present description, “maintaining a contact pressure” refers to any suitable interaction (scraping, maintaining, guiding, and the like) which may take place between the blade 3 of the blade holding device 1 and the roller 5, as can be easily understood by a person skilled in the art.

According to the present invention, and as better shown in FIGS. 1-3, the blade holding device 1 comprises a base 7, a hinge 9, a support plate 11, a blade 3, and biasing means 13. The base 7 may be the same base as that of the assembly in which the blade holding device 1 is used, or may be a separate base, and such a base may be fixed to the ground, or moveable with respect thereto, depending on the particular applications for which the blade holding device 1 and corresponding assembly are intended for, as also apparent to a person skilled in the art.

The hinge 7 preferably has first and second components 15, 17, and as can be easily understood from FIGS. 1-3, the first component 15 is preferably mounted onto the base 7, and the second component 17 is preferably pivotally moveable with respect to the first component 15 about a pivot axis 19. According to a preferred embodiment of the present invention, such a pivot axis 19 is preferably provided by a pin connecting the first and second components 15, 17 together, as illustrated and as is well known in the art.

As also better shown in FIG. 4, the support plate 11 is preferably mounted onto the second component 17 of the hinge 9, and thus is pivotally moveable with respect to the base 7.

From this same FIG. 4, it can also be easily understood that the blade 3 is preferably removably mountable onto a front portion 21 of the support plate 11, the blade 3 being operable between a contact position where the blade 3 rests against the roller 5 for maintaining the contact pressure (see FIGS. 1 and 2), and a retracted position where the blade 3 is drawn away from said roller 5 for removing the contact pressure (see FIG. 3). The ability of the blade holding device 1 to be operated between these two distinct positions is namely possible by means of the hinge 9 and the support plate 11 onto which the blade 3 is mounted, as shown in FIG. 4. Moreover, as will be easily understood from the following description, the blade holding device 1 according to the present invention, by virtue of its different components, namely its hinge 9, its support plate 11, its biasing means 13, and the like, is enabled to have its blade 3 operated continuously in a contact position, onto the roller 5, and this throughout substantial changes in diameter of the roller 5, whether the roller 5 is increased or decreased in diameter, as can be easily understood when contrasting FIGS. 1 and 2, and as also apparent to a person skilled in the art.

Indeed, an important aspect of the present invention resides in that the blade holding device 1 comprises biasing means 13, the biasing means 13 being operatively connected between the base 7 and the support plate 11 for biasing the support plate 11 and corresponding blade 3 into the contact position. Thus, a main function of the biasing means 13 is to ensure that the blade 3 which is mounted onto the support plate 11 is constantly urged onto the roller 5 for maintaining a contact pressure thereon, that is, to ensure that the blade 3 is kept in the contact position. Thus, it may be appreciated that the biasing means 13 according to the present invention may take on various suitable embodiments, while still carrying out the above-mentioned function. Indeed, FIGS. 7-11 illustrate a few examples of how the biasing means 13 may be disposed otherwise onto the blade holding device 1 according to the present invention. Different suitable biasing means 13 and dispositions thereof on the blade holding device 1, other than the ones described or illustrated herein, may obviously be used according to the scope of the present invention, as apparent to a person skilled in the art.

In order to selectively trigger the blade holding device 1 away from the contact position, that is, in order to “override” the biasing means 13, the blade holding device 1 according to the present invention preferably also comprises retracting means 23 for operating the support plate 11 and corresponding blade 3 into the retracted position. Similarly to the biasing means 13, the retracting means 23 according to the present invention may take other suitable embodiments than those described and illustrated herein, in order to carry out the above-mentioned function, as also apparent to a person skilled in the art.

For example, according to a preferred embodiment of the present invention, the retracting means 23 preferably comprise a hinge 29 similar to the above-mentioned first hinge 9. This second hinge 29 preferably has first and second components 31, 33, the first component 31 being mounted onto the base 7, and the second component 33 being pivotally moveable with respect to the first component 31 about a pivot axis 35, as can also be easily understood when referring to FIGS. 5 and 6. Once again, the pivot axis 35 preferably takes the form of a pin for connecting the first and second components 31, 33 to each other, as can be easily understood. Moreover, the base 7 of the second hinge 29 is preferably the same base 7 as that of the first hinge 9, but ultimately, the second hinge 29 could also be placed onto a separate base, as apparent to a person skilled in the art.

Moreover, the retracting means 23 also preferably comprise a lever 37, said lever 37 being mounted onto the second component 33 of the second hinge 29, and thus being pivotally moveable with respect to the base 7, as can also be easily understood when referring to FIGS. 5 and 6. The lever 37 preferably has a front portion 39 cooperating with a rear portion 41 of the support plate 11 for displacing the same so as to reactively displace the front portion 21 of the support plate 11 and corresponding blade 3 away from the roller 5, into the retracted position, as can be easily understood when contrasting FIGS. 5 and 6. In this particular embodiment, the front portion 39 of the lever 37 is used to push down onto a corresponding component provided on the rear portion 41 of the support plate 21 and thus in turn have said support plate 11 rotated about its corresponding hinge 9 (or pivot axis 19), so as to raise the front portion 21 of the support plate 11, and thus raise the blade 3 away from the roller 5. Once again, the front portion 39 of the lever 37 and the rear portion 41 of the support plate 11 may take on various suitable embodiments in order to carry out the above-mentioned function, as apparent to a person skilled in the art. Moreover, in the context of the present description, the words “raising” and “lowering” are relative, and may be used conversely, depending at which location the blade holding device 1 is positioned about the roller 5, as can also be easily understood by a person skilled in the art.

According to another preferred embodiment of the invention, the retracting means 23 further comprise a retracting arm 43, better illustrated in FIGS. 5 and 6. The retracting arm 43 is preferably pivotally mountable onto the base 7 and is preferably provided with a cam 45. The cam 45 is preferably positioned adjacent to the lever 37, and it is shaped and sized so that when the retracting arm 43 is operated into a first configuration, the cam 45 is away from said lever 37, as better shown in FIG. 5, thereby enabling the biasing means 13 to bias the support plate 11 and corresponding blade 3 into the contact position. In contrast, as better shown in FIG. 6, when the retracting arm 43 is operated into a second configuration, the cam 45 presses against the lever 37 so as to displace the same, and in turn displaces the support plate 11 and corresponding blade 3 into the retracted position, as can be easily understood. It is worth mentioning also that according to the present invention, the retracting arm 43 may be provided with a suitable number of cams 45 disposed accordingly along a transversal width of the lever 37, in order to appropriately and uniformly press against the lever 37, as can be easily understood by a person skilled in the art. Moreover, instead of having a retracting arm 43 and corresponding cam(s) 45 positioned rearwardly from the support plate 11, and cooperating with said support plate 11 via a lever 37, a similar type of retracting arm 43 and corresponding cam(s) 45 could be provided in a front portion of the base 7, and devised so that the cam(s) 45 would directly press against the support plate 11 so as to operate it into the retracted position. In such a case, this embodiment would be preferably provided with a suitable splashguard so as to avoid that any debris originating from the roller 5 or other source may accumulate itself onto the retracting arm 43 and corresponding cam system.

Furthermore, as aforementioned, various other suitable embodiments rather than the above-mentioned retracting arm 43 and cam 45 may be used to operate the lever (or simply the support plate 11, for that matter) in order to trigger the support plate 11 and corresponding blade 3 either into a contact position, or a retracted position, as also apparent to a person skilled in the art. For example, the retracting means 23 could simply consists of the support plate 11 itself, which would be operated (i.e. pivoted) accordingly, in order to draw the blade 3 away from the roller 5, and into the retracted position.

However, it can be easily understood that the above-described retracting means 23 are advantageous in that they enable to easily, quickly, selectively and remotely operate the support plate 11 and corresponding blade 3 between the contact and retracted positions. It should be also understood that these retracting means 23, although advantageous, are not absolutely essential to the invention, in that, ultimately, the support plate 11 may act itself as the most basic retracting means 23, as aforementioned, that is, the support plate 11 may be operated manually or mechanically (with pistons, etc.) in order to have the support plate 11 and corresponding blade 3 operated between contact and retracted configurations, as can be easily understood by a person skilled in the art.

According to the preferred embodiment of the present invention, the biasing means 13 preferably comprise a plurality of springs 47 disposed along a transversal width of the support plate 11, in a direction substantially parallel to the pivot axis 19 of the hinge 9 supporting the plate 11, as can be easily understood from FIGS. 1-11. The biasing means 13 according to the present invention preferably consists of compression springs 47, for example, and are preferably disposed in a manner so as to create a constant force on the blade 3 via the support plate 11, which thus enables the blade 3 to be in continuous contact with the roller 5 in a constant manner (contact pressure, preferably), and this for extended periods of time, without maintenance and/or servicing.

According to another important aspect of the present invention, the blade holding device 1 preferably comprises a casing 49 for containing such springs 47 within the casing 49. This enables namely to avoid having any projecting components of the blade holding device 1 which may adversely cooperate with other components of the assembly, such as rollers 5, and the like (paper bands from the rollers 5, etc.), and most importantly, prevents the springs 47 from being substantially contaminated from any debris which may be accumulated thereon from the rollers 5 and other components of the assembly, thereby enabling the springs 47 to carry out their corresponding biasing action, also for extended periods of time, and in a substantially trouble-free manner. The springs 47 could operate without the casing 49, but the presence of such casing 49 is beneficial, as explained above and as can be easily understood by a person skilled in the art.

As can be easily understood from FIGS. 16-18, the casing 49 according to the preferred embodiment of the present invention preferably comprises first and second parts 51, 53, said parts 51, 53 being nestable into one another and being slidably moveable with respect to each other so as to compensate for changes in length of the springs 47 contained within the casing, and thus enabling the springs 47 to either expand or be compressed depending on the positioning (angle, etc.) of the support plate 11 and corresponding blade 3 mounted thereto.

In order to do so, the casing 49 preferably comprises means for ensuring that the first and second parts 51, 53 are slidably moveable with respect to each other, but in such a manner that they do not become detached from one another, and remained nested into one another. The means achievable for enabling the above-mentioned features of the first and second parts 51, 53 of the casing 49 can be very diversified, as apparent to a person skilled in the art. Thus, according to a preferred and most basic embodiment of the present invention, the first part 51 of the casing 49 comprises pairs of diametrically opposed holes 55, each pair of holes 55 being devised for receiving a corresponding fastener 57, and the second part 53 of the casing 49 preferably comprises corresponding pairs of diametrically opposed oblong orifices 59, each pair of oblong orifices 59 being devised for receiving a fastener 57 of a corresponding pair of holes 55 and for thus allowing said fastener 57 to slidably move along said pair of oblong orifices 59, as can be better understood when referring to FIGS. 17 and 18. Indeed, the fasteners 57 (or pins, etc.) which are inserted into the corresponding pairs of holes 55 thus act as stoppers when they abut with the edges of the oblong orifices 59, and the length of these oblong orifices 59 determine the extent to which the springs may either expand or be compressed. Thus, it can be easily understood by a person skilled in the art that by changing these parameters (lengths of first and second parts 51, 53 of the casing 49; positioning of holes 55; positioning of oblong orifices 59; length of oblong orifices 59; etc.), the limits of the array of different pivoting angles achievable by the support plate 11 and corresponding blade 3 may be altered accordingly.

Alternatively, the blade holding device 1 according to the present invention may be provided with a casing 49 having first and second parts 51, 53 such as the ones illustrated in FIGS. 19-23, wherein the first and second parts 51, 53 of the casing 49 are deprived of any holes 55 or orifices 59, thereby further preventing the contamination of the springs 47 contained within the casing 49, as can be easily understood by a person skilled in the art. In this case, instead of using the above-mentioned holes 55, orifices 59, and fasteners 57, for ensuring a slidable movement between the first and second parts 51, 53, other suitable means, such as telescopic arms, piston cylinders 71, and the like, as exemplified in FIGS. 19-21, are preferably used, as can be easily understood by a person skilled in the art. FIGS. 22 and 23 show views of a casing 49 according to another preferred embodiment of the present invention, said casing 49 containing a single spring 47 within. The above-mentioned casings 47 are preferably provided with suitable sealing means and fasteners 73 for connecting the first and second parts 51, 53 in a suitable and sealed manner, as explained herein.

As can be easily understood from the aforementioned, the numbers of springs 47 to be used, as well as the dimensions thereof, are determined by the force which is required for the application for which the blade holding device 1 is intended for, as apparent to a person skilled in the art. Furthermore, the casing 49 is preferably devised so that the first and second parts 51,53 thereof are nested into one another, and slidably moveable with respect to each other, but in a manner that they do not become detached from one another, that is, enabling them to be operated from top to bottom, that is, enabling them to expand or be compressed depending on whether the spring(s) 47 contained therein need(s) to expand or are compressed. Moreover, it should be also understood that, although according to the preferred embodiment of the present invention there is a plurality of springs 47 contained within a single casing 49, the blade holding device 1 according to the present invention may comprise a plurality of casings 49, each of said casings 49 containing either one single spring 47, or a plurality of such springs 47. As aforementioned, and in order to further illustrate how the biasing means 13 may be disposed in different various other suitable dispositions onto the blade holding device 1 according to the present invention, the biasing means 13 could for example, comprise a magazine 67 positioned within a recess of the base 7 and rotatable with respect to said base 7 about a shaft 69. The magazine 67 would be preferably positioned adjacent to the support plate 11 and comprise a plurality of casings 47 extending radially from the shaft 69. The casings 47 would each comprise a set of springs 47 of different biasing force, and each casing 49 would preferably be interchangeable via a rotation of the magazine 67 about the shaft 69 so as to have a given selected casing 47 operatively cooperate between the base 7 and the support plate 11 for biasing the support plate 11 and corresponding blade 3 into the contact position, as can be easily understood when referring to FIG. 15. Thus, in order to obtain a desired pressure to be maintained onto the blade 3 via the support plate 11, one would simply have to rotate the shaft/magazine until the desired position having the corresponding casing 49 containing the springs 47 of required biasing force, as can be easily understood by a person skilled in the art. Furthermore, instead of springs 47 used as biasing means 13, it is worth mentioning also that according to the present invention, the biasing means 13 themselves can take on other suitable embodiments, such as traction springs, tension springs, and the like, as exemplified in FIGS. 12-14, so long as these biasing means are capable of storing somehow a certain amount of potential energy which may in turn be used for urging the support plate 11 and corresponding blade 3 into the contact position, as explained hereinabove.

In an attempt to ensure an easy interchangeability of the various components of the blade holding device 1, the first part 51 of the casing 49 preferably comprises securing means 52 for operatively securing the casing 49 via its first part 51 onto the support plate 11, in a quick and easy manner, and the second part 53 of the casing 49 also comprises securing means 54 for operatively securing the casing 49 via its second part 53 onto the base 7, in a similar manner. These securing means 52,54 may take on various different suitable embodiments, such as tracks, fasteners, and the like, as illustrated herein and as apparent to a person skilled in the art. The purpose of these securing means 52,54 is to enable to secure the positioning of either the top or bottom portion of the casing 49 onto a corresponding portion of the blade holding device 1, typically the support plate 11 and the base 7 respectively, so as to ensure that the casing 49 and the springs 47 contained therein, namely the biasing means 13, are positioned and kept into place appropriately, while enabling them to carry out their corresponding biasing function, so as to urge the support plate 11 and corresponding blade 3 into the contact position, as explained hereinabove.

In a further attempt to ease the interchangeability of the various components of the blade holding device 1 according to the present invention, the front portion 21 of the support plate 11 preferably comprises a support lip 61, such that an edge of the blade 3 may be slidably insertable into a slot defined between the support lip 61 and the support plate 11, as better shown in FIG. 4. Preferably also, the edge of the blade comprises a bulge 63, and the support lip 61 comprises a rim 65, so that the bulge 63 of the blade 3 be devised for abutting with the rim 65 of the support lip 61 and thus prevent the blade 3 from being easily removed from the slot when inserted therein, as can also be easily understood when referring to FIG. 4. It is worth mentioning though that according to the present invention, other suitable means for enabling the blade 3 to be removably, easily, quickly, and securably mounted onto the front portion 21 of the support plate 11 may be used, as also apparent to a person skilled in the art.

According to the present invention, the blade holding device 1 and the corresponding components thereof are preferably made of suitable materials so as to sustain the loading conditions and the working environments for which the blade holding device 1, and corresponding assembly, are intended for, as apparent to a person skilled in the art. Being typically used in the pulp and paper industry, the blade holding device 1 according to the present invention is preferably designed to be used in an environment at high temperatures, as well as in very humid conditions. As can be easily understood from the present description, the blade holding device 1 according to the present invention may easily replace conventional blade holders, such as the ones of type DST and KF, at any given position and location within a conventional assembly or machine.

As briefly explained herein, several components of the blade holding device 1 are completely closed (namely the springs 47 contained within the casing 49) to prevent that they be obstructed by paste fibers, dust and the like. The retracted position for the changing of a blade 3, for example, is activated by a cam-retractor system complementary to the blade holding device 1. It is also possible to activate the opening by means of a pressure-rig lever arm or even by means of pneumatic actuators, which would cooperate with the support plate 11 in a suitable manner, as explained above and as apparent to a person skilled in the art.

As shown in the accompanying drawings, the loading system is mainly driven by means of biasing means 13, such as compression springs 47 for example, which are disposed in a manner so as to create a constant force on the blade holding device 1, which enables the blade 3 to be in contact with the roller 5 in a constant manner and this without maintenance, for extended periods of time of intense service, whereas the loading of the DST blade-holder, for example, is carried out by means of hoses such as those used for fires, or rubberized, which dry up and deteriorate after some time. This determining factor is a very important point to be considered since the great losses of time related to maintenance increase the costs of production of paper considerably.

As briefly explained and illustrated herein, the blade holding device 1 according to the present invention does not require any control panel contrary to that of DST blade-holders which requires even more maintenance. Furthermore, the blade holding device 1 according to the present invention is by far superior to the blade-holders of type KF and KB which are rigid and do not offer any flexibility, that is, cannot match in a uniform manner the surface of the rollers, when the latter go through substantial changes in diameter, as is only possible with the blade holding device 1 of the present invention (better appreciated when contrasting FIGS. 1 and 2).

The blade holding device 1 according to the present invention as well as the different embodiments thereof can be secured to the frame of the scraper or can be mounted onto tracks, in this manner they can be replaced easily by removing them via the extremities of the scraper.

According to the present invention, and as explained hereinabove, the loading system is carried out by means of biasing means 13, such as springs 47, irrespectively of the disposition, the shape, the nature, the dimensions or the material used for the manufacturing thereof, and thus any variations from the present invention, as can be easily understood from the preceeding embodiments by a person skilled in the art, is considered to be within the scope of the present invention.

As mentioned above, according to another aspect of the present invention, there is provided an assembly comprising a roller and a blade holding device 1 such as the one described herein and such as the one exemplified in the accompanying drawings. It is to be understood that according to another aspect of the present invention, there is also provided a method of operating the above-mentioned blade holding device 1 and/or assembly. Furthermore, according to yet another aspect of the present invention, there is also provided a kit with components for assembling the above-mentioned blade holding device 1 and/or assembly.

In regards to the setting of the operation pressures according to a preferred embodiment of the present invention, one simply has to obtain the equivalent pressure to that of the PSI required. Pressure tests are preferably carried out by means of a closed hose at the end linked to a manometer in which compressed air is sent and then one adjusts the desired pressure. As can be easily understood by a person skilled in the art, when the blade holding device 1 is parallel, the pressure is equivalent to the PSI indicated in the manometer. Thus, for example: by knowing that three (3) springs of 2″ long with a spiral of ⅝″ and a diameter of 0.080″ mounted inside of the compression system body on a distance of 18″ is equivalent to approximately 10 PSI.

As may now be appreciated, the present invention is a substantial improvement over the prior art in that by virtue of its design and components, the blade holding device 1 according to the present invention a) has a loading system requiring substantially no maintenance and is thus a revolutionary concept since the arrival on the market of the DST blade-holders; similarly to the DST, it can be mounted on a plate of about 0.060 inches, but with the added advantage of enabling different thicknesses, shapes and configurations; b) has a revolutionary loading system operated by means of a closed system without maintenance nor control panel and comprising a flexibility equal and/or superior to that what is best done presently in the market; c) requires little or virtually no maintenance because it does not rely on a hose that may dry up, and offers also a continuous contact pressure and does not require any control box; d) is designed for working in an environment at high temperatures as well as in very humid conditions; e) can be provided on conversion sets for replacing DST and KF systems; and f) can be used on new equipment as well as current equipment. Moreover, the present invention is also advantageous in that it may be operated manually or automatically, directly or remotely.

As may now also be better appreciated, the present invention is a substantial improvement over other related blade holding devices of the prior art in that, by virtue of its design and components, the blade holding device 1 according to the present invention a) has a much more simpler design enabling the components thereof to be easily interchangeable and/or serviced, if need may be; b) prevents any debris from the roller 5 from being accumulated onto the springs 47 because the latter are contained within a corresponding casing 49; c) the support plate 11 mounted on the hinge 9 and corresponding blade 3 are thus intended to follow the roller 5 through a substantial change in diameter of the roller 5 (see and contrast FIGS. 1 and 2), without the need for repositioning the blade holding device 5 and/or replacing the blade 3 itself; d) is intended to have its blade 3 maintained onto the roller 5 in a continuous manner, and this throughout a wide range of roller diameters; and e) has components and dispositions which enable the blade 3 to be easily, quickly, and adjustably operated between contact and retracted positions.

Of course, numerous modifications could be made to the above-described embodiments without departing from the scope of the invention, as defined in the appended claims. 

1. A blade holding device for selectively and adjustably maintaining a contact pressure onto a neighboring roller, the device comprising: a base; a hinge having first and second components, the first component being mounted onto the base, and the second component being pivotably moveable with respect to the first component about a pivot axis; a support plate, said support plate being mounted onto the second component of the hinge, and thus being pivotably moveable with respect to the base; a blade being removably mountable onto a front portion of the support plate, the blade being operable between a contact position where the blade rests against the roller for maintaining the contact pressure, and a retracted position where the blade is drawn away from said roller for removing the contact pressure; and biasing means, the biasing means being operatively connected between the base and the support plate for biasing the support plate and corresponding blade into the contact position.
 2. A blade holding device according to claim 1, wherein the device comprises retracting means for operating the support plate and corresponding blade into the retracted position.
 3. A blade holding device according to claim 1, wherein the device comprises retracting means for operating the support plate and corresponding blade into the retracted position, said retracting means comprising: a hinge having first and second components, the first component being mounted onto the base, and the second component being pivotably moveable with respect to the first component about a pivot axis; and a lever, said lever being mounted onto the second component of the hinge of the retracting means, and thus being pivotably moveable with respect to the base, said lever having a front portion cooperating with a rear portion of the support plate for displacing the same so as to reactively displace the front portion of the support plate and corresponding blade away from the roller, into the retracted position.
 4. A blade holding device according to claim 3, wherein the retracting means comprise a retracting arm, the retracting arm being pivotably mountable onto the base and being provided with a cam, the cam being positioned adjacent to the lever, and being shaped and sized so that when the retracting arm is operated into a first configuration, the cam is away from said lever, thereby enabling the biasing means to bias the support plate and corresponding blade into the contact position, and when the retracting arm is operated into a second configuration, the cam presses against the lever so as displace the same, and in turn displace the support plate and corresponding blade into the retracted position.
 5. A blade holding device according to claim 1, wherein the biasing means comprise a plurality of springs disposed along a transversal width of the support plate, in a direction substantially parallel to the pivot axis of the hinge supporting the support plate.
 6. A blade holding device according to claim 5, wherein the biasing means comprise a casing for containing the springs within said casing.
 7. A blade holding device according to claim 6, wherein the casing comprises first and second parts, said parts being nestable into one another and being slidably movable with respect to each other so as allow the springs to either expand or be compressed within the casing.
 8. A blade holding device according to claim 7, wherein the first part of the casing comprises pairs of diametrically opposed holes, each pair of holes being devised for receiving a corresponding fastener, and wherein the second part of the casing comprises corresponding pairs of diametrically opposed oblong orifices, each pair of oblong orifices being devised for receiving a fastener of a corresponding pair of holes and for allowing said fastener to slidably move along said pair of oblong orifices.
 9. A blade holding device according to claim 6, wherein the first part of the casing comprises securing means for operatively securing the casing onto the support plate.
 10. A blade holding device according to claim 6, wherein the second part of the casing comprises securing means for operatively securing the casing onto the base.
 11. A blade holding device according to claim 1, wherein the front portion of the support plate comprises a support lip, an edge of the blade being slidably insertable into a slot defined between the support lip and the support plate.
 12. A blade holding device according to claim 11, wherein the edge of the blade comprises a bulge, and wherein the support lip comprises a rim, the bulge of the blade being devised for abutting with the rim of the support lip, when the edge of the blade is inserted into the slot, so as to prevent the blade from being easily removed from said slot.
 13. A blade holding device according to claim 1, wherein the biasing means comprise a magazine positioned within a recess of the base and rotatable with respect to said base about a shaft, said magazine being positioned adjacent to the support plate and comprising a plurality of casings extending radially from the shaft, the casings comprising each within the same a set of springs of different biasing force, and each casing being interchangeable via a rotation of the magazine about the shaft so as to have a given selected casing operatively cooperate between the base and the support plate for biasing the support plate and corresponding blade into the contact position.
 14. An assembly comprising: a roller; and a blade holding device positioned adjacent to the roller for selectively and adjustably maintaining a contact pressure onto said roller, the device comprising: a base; a hinge having first and second components, the first component being mounted onto the base, and the second component being pivotably moveable with respect to the first component about a pivot axis; a support plate, said support plate being mounted onto the second component of the hinge, and thus being pivotably moveable with respect to the base; a blade being removably mountable onto a front portion of the support plate, the blade being operable between a contact position where the blade rests against the roller for maintaining the contact pressure, and a retracted position where the blade is drawn away from said roller for removing the contact pressure; and biasing means, the biasing means being operatively connected between the base and the support plate for biasing the support plate and corresponding blade into the contact position.
 15. An assembly according to claim 14, wherein the device comprises retracting means for operating the support plate and corresponding blade into the retracted position.
 16. An assembly according to claim 14, wherein the device comprises retracting means for operating the support plate and corresponding blade into the retracted position, said retracting means comprising: a hinge having first and second components, the first component being mounted onto the base, and the second component being pivotably moveable with respect to the first component about a pivot axis; and a lever, said lever being mounted onto the second component of the hinge of the retracting means, and thus being pivotably moveable with respect to the base, said lever having a front portion cooperating with a rear portion of the support plate for displacing the same so as to reactively displace the front portion of the support plate and corresponding blade away from the roller, into the retracted position.
 17. An assembly according to claim 16, wherein the retracting means comprise a retracting arm, the retracting arm being pivotably mountable onto the base and being provided with a cam, the cam being positioned adjacent to the lever, and being shaped and sized so that when the retracting arm is operated into a first configuration, the cam is away from said lever, thereby enabling the biasing means to bias the support plate and corresponding blade into the contact position, and when the retracting arm is operated into a second configuration, the cam presses against the lever so as displace the same, and in turn displace the support plate and corresponding blade into the retracted position.
 18. An assembly according to claim 14, wherein the biasing means comprise a plurality of springs disposed along a transversal width of the support plate, in a direction substantially parallel to the pivot axis of the hinge supporting the support plate, and wherein the biasing means further comprise a casing for containing the springs within said casing, the casing comprising first and second parts, said parts being nestable into one another and being slidably movable with respect to each other so as allow the springs to either expand or be compressed within the casing.
 19. An assembly according to claim 18, wherein the first part of the casing comprises pairs of diametrically opposed holes, each pair of holes being devised for receiving a corresponding fastener, and wherein the second part of the casing comprises corresponding pairs of diametrically opposed oblong orifices, each pair of oblong orifices being devised for receiving a fastener of a corresponding pair of holes and for allowing said fastener to slidably move along said pair of oblong orifices, and wherein the first and second parts of the casing each comprise securing means for operatively securing the casing onto the support plate and base respectively.
 20. An assembly according to claim 14, wherein the front portion of the support plate comprises a support lip, an edge of the blade being slidably insertable into a slot defined between the support lip and the support plate, and wherein said edge of the blade comprises a bulge, the support lip comprising a rim and the bulge of the blade being devised for abutting with said rim, when the edge of the blade is inserted into the slot, so as to prevent the blade from being easily removed from said slot. 